• Title/Summary/Keyword: Covering materials

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Suggestion for the Future of Protected Vegetable Crops Culture in Chungnam (충남지방의 시설채소 재배동향과 앞으로의 방향)

  • Lee, Young Bok;Kang, Jae Chol
    • Korean Journal of Agricultural Science
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    • v.17 no.1
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    • pp.18-25
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    • 1990
  • The above results indicate that vegetable crop production using vinyl houses continously increases. However, technical support and facility improvement are still insufficent to establish a full production system. In order to improve the cultural environment in facilities for better vegetable culture, several facters should be considered. 1. Facility design and arrangement should be made to improve micro-environments for crop growth and development because direction of facility and covering materials can affect the amount of light trasmitted into vinyl houses. 2. Cultivation of several leading varieties in each crop may not provide stable production and profit especially under undesirable environmental conditions. Thus, it is required to grow not only leading varieties but also other cultivars to decrease the economic losses. 3. Crops should be carefully managed when planted in early season not to experience low temperatures which induce growth retards. Early season cultivation requires proper selection of cultivars which are resistant to low temperture. 4. Active control of micro-environment in facilities should be made via improving the ventilation and irrigation systems.

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Study on Leaf Production of Angelica acutiloba by Mulching with Polyethylene Film

  • Choi, Seong-Kyu;Yun, Kyeong-Won;Chon, Sang-Uk;Seo, Young-Nam;Seo, Kyoung-sun;Kwon, Byung-Sun
    • Plant Resources
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    • v.6 no.3
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    • pp.211-214
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    • 2003
  • This study was conducted to produce effectively more leaves of Angelica acutiloba through year-round production system by using various mulching materials and polyethylene(PE) tunnel. Soil temperature by covering treatment was higher in PE mulching and PE tunnel than in rice straw mulching, especially showing the highest temperature in PE tunnel from April through May. Water content of soil was higher in PE mulching than in non-mulching. Leaf production of Angelica acutiloba through year-round production showed the highest in PE tunnel and root production in PE mulching. These results suggest that leaf production of Angelica acutiloba can be maximized through PE tunnel cultivation system.

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Evaluation of Floor Impact Sound Performance according to the Reduction Methods (바닥충격음 저감방안에 따른 성능평가)

  • Choi Gyoung-Seok;Choi Hyun-jung;Yang Kwan-Seop;Kim Kyoung-Woo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.14 no.9 s.90
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    • pp.811-818
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    • 2004
  • Impact sounds, such as those created by footsteps, the dropping of an object or the moving of furniture, can be a source of great annoyance in residential buildings. The character and level of impact noise generated depends on the object striking the floor, on the basic structure of the floor, and on the floor covering. This study base on the evaluate of isolation performance of impact sound according to the impact noise reduction methods. Reduction methods consist of four ways. First way is increase thickness of bare floor and other ways are using the soft coverings on the floor and ceiling assembles. Last way is make floating floor with shock absorbing materials.

A Bibliographical Analysis on the Characteristics of the Articles Dealing with Architecture in the Chapter of Seomyongji of Imwongyeongjeji (서지학적 분석을 통한 임원경제지 섬용지 영조기사의 구성과 특징 연구)

  • Lee, Kang-Min
    • Journal of the Korean housing association
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    • v.21 no.4
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    • pp.59-69
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    • 2010
  • Imwongyeongjeji, Administration of Our Daily Life in Woods and Fields, is a sort of encyclopedia compiled by Seo, Yoo Goo in Joseon Dynasty in the 19th century. This voluminous work is made up of 16 chapters with various references including many articles dealing with architecture. The chapter Seomyongji covering the daily necessities contains a number of methods and materials of building construction. The distinctive feature of these articles is that they are mostly from Joseon's books. It is not similar to other chapters which are made of quotations from Chinese books. Especially, he quoted many of articles about architecture from his own work Geumhwagyeongdokgi, Record of Plowing and Reading in Geumhwa. In addition, He selected only empirical knowledge, put it in the book, and commented on it in his judgment. These articles provide valuable information on architectural knowledge in late Joseon period.

The Role of Dynamic Contrast Enhanced MR Mammography in Differentiation between Benign and Malignant Breast Lesions

  • 한송이;차은숙;정상설;김학희;변재영;이재문
    • Proceedings of the KSMRM Conference
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    • 2002.11a
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    • pp.135-135
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    • 2002
  • Purpose: To assess diagnostic accuracy of dynamic contrast enhanced MR mammography in differentiating between benign and malignant lesions. Materials and methods: Ninety-three patients with suspicious mammographic, sonographic or palpable findings underwent pre- or postoperative contrast-enhanced MR imaging of breast using three dimensional fast low-angle shot (3D FLASH) sequence (16/4 msec[repetition time / echo time], 20 flip angle, 3mm slice thickness with no slice gap, 256 by 256 in-plane matrix) covering whole breasts. T1 weighted images were obtained before and after bolus administration of gadopentetate dimeglumine (0.15 mmol/kg). Subtraction images and time-signal intensity curves of region of interest were obtained sequentially and correlated with pathologic diagnoses of lesions.

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Study on Fall Protection from Scaffolds by Plastic Sheets

  • Ohdo, Katsutoshi;Takanashi, Seiji;Hino, Yasumichi;Takahashi, Hiroki;Toyosawa, Yasuo
    • International Journal of Safety
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    • v.10 no.1
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    • pp.10-15
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    • 2011
  • In Japan, protective measures to reduce falls from scaffolds have been strictly applied within industry safety guidelines, and such measures have significantly decreased fatal accidents due to falls from scaffolds. However, the rate of fatal accidents from falls is still high in the construction industries. In order to examine further countermeasures to reduce such falls, the Japan Ministry of Health, Labour and Welfare established a committee in our institute. That committee$\acute{i}$s work experimentally confirmed the effectiveness of using plastic sheets as a covering around scaffolds to protect against falls of construction materials (a method widely used in Japan). However, the workers fell from the space between the work platform and the plastic sheets very occasionally. Based on those results, the plastic sheets were improved for fall protection from the space, and the effect of the improved sheets was confirmed experimentally.

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Exploring Area of Polygons Using Computer Dot Board (컴퓨터로 구성한 점자판에서 면적 개념의 탐구)

  • 고상숙
    • Education of Primary School Mathematics
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    • v.3 no.2
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    • pp.103-107
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    • 1999
  • This article introduces a proposed lesson to help younger or lower level mathematics students conceptualize area. The objective for the proposed lesson was for the student to demonstrate an understanding of the concept of area by identifying the area, in square units, of polygons drawn on computer dot board constructed by computer software, Geometer's Sketchpad. The concept of covering is the key to develop the concept of the area. The article proceeded from rectangular figures, to right-triangular figures, to non-right triangular figures, then to polygons to find the area and develop the formula for the area of the figures. It is meaningful that this kind of materials can be developed within interactive computer environment since students feel successful in loaming and teachers use them directly in their measurement classes.

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Predictions of the maximum plate end stresses of imperfect FRP strengthened RC beams: study and analysis

  • Rabia, Benferhat;Daouadji, Tahar Hassaine;Abderezak, Rabahi
    • Advances in materials Research
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    • v.9 no.4
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    • pp.265-287
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    • 2020
  • A theoretical method to predict the interfacial stresses in the adhesive layer of reinforced concrete beams strengthened with porous FRP plate is presented in this paper. The effect due to porosity is incorporated utilizing a new modified rule of mixture covering the porosity phases. The adherend shear deformations have been included in the present theoretical analyses by assuming a linear shear stress through the thickness of the adherends. Remarkable effect of the porosity has been noted in the results. Indeed, the resulting interfacial stresses concentrations are considerably smaller than those obtained by other models which neglect the porosity effect. It was found that the interfacial stresses are highly concentrated at the end of the FRP plate, the minimization of the latter can be achieved by using porous FRP plate in particular at the end. It is also shown that the interfacial stresses of the RC beam increase with volume fraction of fibers, but decrease with the thickness of the adhesive layer.